Design of mechanical and structural systems is a necessary and ubiquitous process. It can be extremely valuable for designers of mechanical parts and systems to optimize the designs before parts are machined, manufactured, or assembled. For example, the designer of a jet engine necessarily wants to design a turbine which has sufficient strength, ideal heat transfer, lift and drag, but with minimal weight. Further, the turbine designer would desire to consider both heat transfer and fluid flow. Further still, the jet turbine must comply with certain other constraints such as size (diameter, length, etc.). In another example, the designer of a bicycle crankset sprocket (gear) also requires sufficient strength to transmit the force of the pedals to the driving rear wheel but also desires the sprocket to have minimal weight so as not to add unnecessarily to the weight of an assembled bicycle. Such determination of a topology to achieve desired strength and weight, and other characteristics for mechanical objects is an important part of design and manufacturing.
In typical product design, a designer must guess what an analyst needs for optimization. Inter-disciplinary communication is problematic at best. A designer might create a preliminary design. A structural, thermal, aero, financial or other analyst might then study the design and might identify problem spots. With feedback from the analysts, the designer would then revise the design based upon the feedback. The revised design is then returned to the analysts for further study. This iterative process involving the designer and analysts can then generally be repeated to improve the design but, in general, is limited by the available time. Each iteration takes time and in a time-constrained design process, the number of refining iterations must necessarily be limited. There is generally insufficient time for more than one or two optimization cycles.
Topology optimization may also be employed to improve and optimize mechanical designs. Topology optimization may produce results which are more nearly optimal, however, the designer must interpret the results of topology optimization which adds steps to the existing process and increases the time necessary for the design and optimization process. Inter-disciplinary communication can still be problematic. Further, in topology optimization, constraints cannot be directly evaluated which require discrete, smooth geometry including but not limited to, stress constraints, manufacturing cost constraints, thermal contact resistance constraints, skin friction drag constraints etc.
In a typical design process using topological optimization, a designer might run a topology optimization. The designer can interpret the results of the topology optimization to create a preliminary design. This preliminary design can be handed off to an analyst to run size optimization and to identify problem spots. As in the design/structural optimization discussed earlier, once problem spots are identified, the designer can revise the design and hand the revised design back to the structural analyst for further analysis. This iterative process can then be repeated until time constraints force the revised design to be released.